In alkaline medium,$MnO_4^{-}$ oxidises $I^{-}$ to:

Identify the correct statements about the following stoichiometric equation.
$aP_4 + bOH^{-} + cH_2O \longrightarrow dPH_3 + eH_2PO_2^{-}$
$I$. $a+b+c=5$
$II$. $b+c-e=3$
$III$. The oxidation state of $P$ in $H_2PO_2^{-}$ is $+1$.

The $Mn^{3+}$ ion is unstable in solution and undergoes disproportionation to give $Mn^{2+}$,$MnO_2$ and $H^{+}$ ion. Write a balanced ionic equation for the reaction.

The equivalent weight of $Na_2S_2O_3$ (Gram molecular weight $= M$) in the given reaction is $I_2 + 2Na_2S_2O_3 \rightarrow 2NaI + Na_2S_4O_6$.

What is the number of moles of electrons gained by one mole of oxidizing agent in the following redox reaction?
$Zn_{(s)} + 2HCl_{(aq)} \longrightarrow ZnCl_2(aq) + H_2(g)$

In the reaction
$x BrO_3^- + y Cr^{3+} + z H_2O \to Br_2 + CrO_4^{2-} + H^{+}$
the coefficients $x, y, z$ are